Morning brickboard. Well my 87 240 died the other day. It wouldn't start. I jump started the car. Then after about 1 minute of running it died again, so I took the key out of the ignition. I checked the voltage after the death and it was around 12V. So I tried again by jump starting the car. Again it came to life but after a minute of running it died. I left the key in the ignition in the same position of the running car (I think it's the ON position) and I tested the voltage again. The voltage was quickly going down when it got to 7 I went to the car and took the key out. This stopped the voltage from dropping any further. I'm guessing the lights on the dashboard were killing the battery.

Either way the battery is not being charged while the engine is running. My only guess is that it's the alternator, voltage regulator, or brushes. I took out the voltage regulator while leaveing the alternator in place. I'm not sure how long the brushes are suppose to be or how much spring they are suppose to have. I'll post a pic later tonight with a ruler next to the brushes, but they seem long enough. One is much longer than the other. Short brush is about 1/2 inch and long brush about 3/4 inch. What other test can I perform? I'm not sure if i should buy a new regulator. I'd rather replace the regulator than just the brushes since the thing looks very old.